BMW 4 Series: Regular vs. Premium Gas – Which Is Best?
If you’re here, chances are you own a BMW 4 Series, or you’re considering getting one.
Both are exciting prospects!
The BMW 4 Series makes every drive an experience. But, like with all great things, a tiny detail can make a big difference: the type of gas you put in it.
We know what you’re thinking: “It’s just gas, right?” But trust us, the kind of fuel you choose can play a crucial role in how your BMW 4 Series performs, how long it lasts, and even how much you spend on maintenance.
Imagine buying a top-tier smartphone and then using a cheap charger that could potentially harm its battery. Not ideal, right?
The minimum gas type for the BMW 4 Series is mid-grade (89 octane) gas, although BMW recommends premium (91 octane or higher) gas.
By the end of this article, you’ll clearly understand why these recommendations exist.
So, let’s start!
At a Glance: What gas Type does your BMW 4 Series need?
Alright, before we dive deep into the details of octane levels and engine performance, let’s get straight to the answer many of you might be looking for.
After all, sometimes, all we want is a quick and straightforward response, right?
- For a regular BMW 4 Series: If your car is the ‘standard’ model with the 2.0-liter four-cylinder turbo engine (like a BMW 428i or 430i), use mid-grade (89 octane) gas at the very least. However, the experts (and your owner’s manual) recommend using premium (91 octane or higher) gas.
- For a BMW 435i, M440i, or M4: Do you own a BMW 435i, M440i, or even an M4? First off, nice choice! In that case, they all require premium (at least 91 octane) gas.
- Tuned BMW 4 Series: If you’ve given your BMW 4 Series a tune (for example, using a RaceChip), fill them up using premium (at least 91 octane) gas.
Quick note: Occasionally filling up with regular (87 octane) or mid-grade (89 octane) gas won’t necessarily damage your car. But if you want the best for your vehicle for the long term, sticking to the recommendations is the way to go.
If you prefer a table overview, here is what you should know:
| Category | Type | Is It OK? | Notes |
|---|---|---|---|
| Gas | Regular (87 octane) | ! | Not recommended. |
| Gas | Mid-grade (89 octane) | ✓ | Minimum octane rating recommended by BMW, the car will run safely. |
| Gas | Premium (91 octane) | ✓ | Recommended octane rating by BMW, which can prevent knocking sounds and prolong the engine life. |
| Gas | Premium (93 octane) | ✓ | |
| Gas | Ethanol-based (E10) | ✓ | Same as the typical gas at most pumps. |
| Gas | Ethanol-based (E15) | ! | Not optimal for the car, but it won’t be a danger in the short term. |
| Gas | Ethanol-based (E85) | ! | Mostly not OK. It can only be used if your BMW 4 Series has a flex-fuel system. |
| Gas | Reformulated Gasoline (RFG) | ✓ | A type of gas that burns more cleanly, about 30% of the gas sold in the US is RFG. (Source) |
| Additives | Fuel injector cleaner | ! | Be careful; it can potentially damage the engine when overused. |
| Additives | Octane booster | ! | Be careful; it can damage the engine when misused. |
| Additives | Fuel stabilizer | ! | Be careful; it can damage the engine when misused. |
Stick around if you’d like a deeper dive into why these recommendations exist. Otherwise, happy driving, and treat that BMW well!
Does a BMW 4 Series require regular or premium gas?
Time to dive a little deeper!
Per the owner’s manual of a BMW 4 Series, mid-grade gas (89 octane) is the minimum fuel type, but premium gas (91 octane or higher) is recommended:
So, if you fill up your BMW 4 Series with mid-grade (89 octane) gas, it will run safely. However, by using regular (87 octane), you risk damaging the fuel system or engine.
Tip: The correct gas type for your BMW 4 Series will always be written on the inside of the fuel filler cap.
But here’s the thing – just because someone can survive on fast food doesn’t mean it’s the best choice for their health.
Similarly, the engine of your BMW 4 Series is designed to reach its rated performance and consumption values with premium (91 octane) gas. Also, it can positively impact how long your 4 Series will last!
If you own a high-performance version of the BMW 4 Series, like a BMW 435i, M440i, or M4, premium (91 octane or higher) gas is a must.
An occasional tank of regular (87 octane) or mid-grade (89 octane) gas isn’t the end of the world.
However, consistently fueling with a lower octane can lead to issues like engine knocking, reduced power, and even potential long-term engine damage.
And what about a tuned BMW 4 Series?
Modifications like RaceChip can increase the power of your BMW 4 Series.
But when you upgrade the engine’s performance, its diet needs an upgrade too.
Just as an athlete on a rigorous training regime needs specialized nutrition, a tuned BMW 4 Series requires premium (91 octane or higher) gas.
Difference between regular, mid-grade, and premium gas
Fueling up might seem like a mundane task, but there’s a science to it.
Behind each pump, there’s a blend of chemistry designed to make our vehicles run smoothly.
So, if you’ve been wondering, “What do these octane numbers mean?” let’s take a look!
The octane rating of a gasoline type indicates its resistance to knocking or pinging during combustion.
In car terms, knocking is a rattling or pinging sound you’d hear when the air-fuel mixture in the cylinders detonates earlier than it should. It’s not good for your engine!
The higher the octane rating, the more compression the gas can withstand before it ignites, which reduces the likelihood of knocking and leads to smoother engine performance.
When you’re filling up, you will typically see the following gas types:
- Regular gas (87 Octane): Regular gas is the most common and least expensive type of gasoline available at most stations. It’s best for everyday vehicles that don’t demand high performance.
- Mid-grade gas (around 89 Octane): As the name suggests, mid-grade gas sits between regular and premium gasoline in terms of performance and price. Perfect for those who want higher-quality fuel without paying too much.
- Premium gas (91 Octane and above): Designed for high-performance engines, this gas resists knocking and ensures smoother combustion. It’s best for high-performance vehicles, luxury cars, and those with turbocharged engines.
The main difference between regular, mid-grade, and premium gas is that regular gas has an octane rating of 87, mid-grade gas has an octane rating of 89, while premium gas has an octane rating of 91 or higher.
High-end cars (like BMW models) often have advanced engines that run on relatively high compression ratios. These engines thrive on the richness of premium gas, offering better acceleration, fuel economy, and longevity.
Real-world experiences with BMW 4 Series gas choices
Not convinced by the benefits of premium gas? Let’s check out some real-world experiences from BMW 4 Series owners!
1. Weighing the benefits and costs
One BMW 4 Series considers whether saving a few dollars with regular gas is worth it:
You’re driving a car with a turbocharged engine, which is sensitive to octane rating and will lower its power output to meet the lower fuel grade to prevent pre-ignition/detonation. Is it really worth the small difference in price? I never use anything but Shell V-Power in any BMW, normally-aspirated or forced-induction.
Source
2. An accident
Here’s a similar story:
I’ve always run 93 octane in all my vehicles, I’d have no prob running 91 but dont have it where I am in florida. I dont care about the marketing propaganda or any savings hype. Just figured if the manufacturer recommends it I’m going to run it. these cars are not cheap guys, I’ll pay 130 bucks more a year for gas to keep it running in tip top.
Source
3. The importance of premium gas in a tuned car
Here’s a BMW 435i owner who has tuned his car and only fills it with 100-octane premium gas:
Well to make some of you feel better. I only pour 100 octane into my daily driven F32 435i, $6.99 a gallon.
Source
My car is however FBO MHD stage 2+ 95 oct tuned.
Can you use ethanol-based fuels for the BMW 4 Series?
Ethanol-based fuels are fuels that contain ethanol, which is a renewable fuel made from biomass. Biomass consists of a variety of plant materials.
It looks something like this:
That’s a joke, of course!
In reality, over 98% of gasoline in the US contains ethanol. The most common ethanol-based fuel is E10, which consists of 10% ethanol and 90% gasoline.
Ethanol-based fuels reduce air pollution, but at the same time, using gas that contains a high concentration of ethanol can damage your vehicle.
E10 is a standard that’s commonly accepted to be safe for most cars on the road today, including the BMW 4 Series.
However, you may occasionally find E15 gas containing 15% ethanol and 85% gasoline. In the US, E15 can be found in 30 states at over 2,400 pumps (source).
E15 is not optimal for the BMW 4 Series, but it won’t be a danger in the short term. However, it can only be used for BMW 4 Series models from 2015 or newer.
Once you increase the ethanol percentage further, it really won’t be too good for your car.
For instance, E85 gas is also available in some places, but it can only be used for your BMW 4 Series if you have a flex-fuel kit.
FAQs about gas for the BMW 4 Series
If you have any more questions about which gas to use for your BMW 4 Series, take a look at these FAQs:
What happens if I accidentally fill up with regular gas in my BMW 4 Series?
Filling your BMW 4 Series with regular gas once won’t cause immediate harm. However, you might notice reduced performance and engine knocking. To prevent potential issues, it’s a good idea to top off with premium gas on your next fill-ups. Consistently using regular gas isn’t advised, as it can lead to long-term engine issues.
Can I use fuel additives for the BMW 4 Series?
You can use fuel additives or cleaners for the BMW 4 Series. However, it is important to carefully read the manual beforehand and avoid using additives more than twice a year, as this can damage the engine or fuel system.
Can the BMW 4 Series take 93 gas?
Filling up a BMW 4 Series with premium (93 octane) gas will allow it to extract its maximum performance and engine longevity. However, unless you have a high-performance model, 91 octane is just as good.
Final verdict
To put it short: Can you run your BMW 4 Series on regular gas?
From our research, the answer is no.
It’s better to use mid-grade gas, and it’s best to use premium gas.
BMW isn’t randomly suggesting premium gas for fun.
It’s all about preserving that engine and guaranteeing your 4 Series continues to drive for years to come.
Sure, in the short run, you might save a bit by using regular gas. But think about the long game: lower fuel efficiency and potential repair bills. Suddenly, those upfront ‘savings’ might not feel so significant.
If you have any more questions, let us know in the comments!
Gas requirements for other BMW models
Are you interested in the required gas type of other BMW models?
If so, you can find everything you need to know in the following articles:
